It is the latest in the company's transparency efforts, which have included disclosing the presence of 368 skin allergens and revealing detailed fragrance ingredients for its products online.

The company’s sustainability report, The Science Within, gives a detailed breakdown of how ingredients are evaluated for its household brands, including Glade, Pledge and Mr Muscle.

It details how ingredients undergo a four-step evaluation of their potential impact on human health and the environment, which looks at both hazard and risk.

The ingredients are assessed for:

chronic human health hazards;

long-term environmental hazards;

acute risks to human and environmental health; and

other potential effects such as allergic reactions

'Leader in transparency'

Boma Brown-West, senior manager of consumer health for the NGO, the Environmental Defense Fund (EDF), said SC Johnson continues to "be a leader when it comes to transparency – first long ago on ingredient identity, now on its ingredient assessment methodology".

"It is clear that SC Johnson’s Greenlist methodology was rigorously designed, and that the company is not afraid to evolve its methodology in its pursuit of safer products," she told Chemical Watch.

Nneka Leiba, director of healthy living science at the NGO, Environmental Working Group (EWG), said: "It is always welcome news for consumers when companies like SC Johnson take concrete steps to increase transparency and disclose more information about the chemical ingredients in their products."

And US NGO, Women Voices for the Earth (WVE), director of corporate accountability, Sarada Tangirala, said the report offers "a level of detail and specificity in its approach to chemical screening and safety that we have not seen before in a cleaning products company."

"Their candidness and point of view clearly reflects a thoughtful approach to living their values, and also a responsiveness to consumer concerns around chemical safety and reducing harm," she added

Ms Tangirala said that SC Johnson is "driving the whole industry to be better" and she hoped other companies would follow its example.

"At a minimum, we want to see all cleaning product companies offering the same level of transparency in their chemical screening programmes, so that we can start to compare companies on their specific standards and criteria," she said.

There has been increasing pressure for ingredient transparency in consumer goods products in the US. In October 2017, California's Cleaning Products Right to Know Act (SB258) was signed into law. This requires "chemicals of concern" including fragrance ingredients in products in the state, to be listed on the item's label.

Brian Sansoni, vice president of sustainability initiatives at the American Cleaning Institute (ACI), said SC Johnson’s disclosure was "yet another example of how cleaning product manufacturers are providing more information than ever on their products and ingredients."

Last year, Unilever US made fragrance ingredient information for more than 100 products available online and through an app.

US consumer goods giant, Procter & Gamble, also said it will reveal the fragrance ingredients, down to 0.01% of content, for all products sold in the US and Canada by the end of 2019.